Proceedings. 14th Symposium on Logic in Computer Science (Cat. No. PR00158)

5-5 July 1999

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  • Proceedings. 14th Symposium on Logic in Computer Science (Cat. No. PR00158)

    Publication Year: 1999
    Request permission for reuse | PDF file iconPDF (311 KB)
    Freely Available from IEEE
  • Some decision problems of enormous complexity

    Publication Year: 1999, Page(s):2 - 12
    Cited by:  Papers (2)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (93 KB)

    We present some new decision and comparison problems of unusually high computational complexity. Most of the problems are strictly combinatorial in nature; others involve basic logical notions. Their complexities range from iterated exponential time completeness to /spl isin//sub 0/ time completeness to /spl theta/(/spl Omega//sup /spl omega//,0) time completeness to /spl theta/(/spl Omega//sub /s... View full abstract»

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  • Two-variable descriptions of regularity

    Publication Year: 1999, Page(s):14 - 23
    Cited by:  Papers (3)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (206 KB)

    We prove that the class of all languages that are definable in /spl Sigma//sub 1//sup 1/(FO/sup 2/), that is, in (non-monadic) existential second-order logic with only two first-order variables, coincides with the regular languages. This provides an alternative logical description of regularity to both the traditional one in terms of monadic second-order logic, due to Buchi and Trakhtenbrot, and t... View full abstract»

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  • The two-variable guarded fragment with transitive relations

    Publication Year: 1999, Page(s):24 - 34
    Cited by:  Papers (18)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (393 KB)

    We consider the restriction of the guarded fragment to the two-variable case where, in addition, binary relations may be specified as transitive. We show that (i) this very restricted form of the guarded fragment without equality is undecidable and that (ii) when allowing non-unary relations to occur only in guards, the logic becomes decidable. The latter subclass of the guarded fragments the one ... View full abstract»

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  • Logics with aggregate operators

    Publication Year: 1999, Page(s):35 - 44
    Cited by:  Papers (5)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (365 KB)

    We study adding aggregate operators, such as summing up elements of a column of a relation, to logics with counting mechanisms. The primary motivation comes from database applications, where aggregate operators are present in all real life query languages. Unlike other features of query languages, aggregates are not adequately captured by the existing logical formalisms. Consequently, all previous... View full abstract»

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  • Guarded fixed point logic

    Publication Year: 1999, Page(s):45 - 54
    Cited by:  Papers (23)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (232 KB)

    Guarded fixed point logics are obtained by adding least and greatest fixed points to the guarded fragments of first-order logic that were recently introduced by H. Andreka et al. (1998). Guarded fixed point logics can also be viewed as the natural common extensions of the modal p-calculus and the guarded fragments. We prove that the satisfiability problems for guarded fixed point logics are decida... View full abstract»

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  • Towards a theory of bisimulation for local names

    Publication Year: 1999, Page(s):56 - 66
    Cited by:  Papers (10)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (163 KB)

    A.M. Pitts and I.D.B. Stark (1998) have proposed the v-calculus as a language for investigating the interaction of unique name generation and higher-order functions. They developed a sound model based on logical relations, but left completeness as an open problem. In this paper, we develop a complete model based on bisimulation for a labelled transition system semantics. We show that bisimulation ... View full abstract»

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  • Weak bisimulation and open maps

    Publication Year: 1999, Page(s):67 - 76
    Cited by:  Papers (7)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (230 KB)

    A systematic treatment of weak bisimulation and observational congruence on presheaf models is presented. The theory is developed with respect to a "hiding" functor from a category of paths to observable paths. Via a view of processes as bundles, we are able to account for weak morphisms (roughly only required to preserve observable paths) and to derive a saturation monad (on the category of presh... View full abstract»

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  • Elementary axioms for categories of classes

    Publication Year: 1999, Page(s):77 - 85
    Cited by:  Papers (4)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (146 KB)

    We axiomatize a notion of "classic structure" on a regular category, isolating the essential properties of the category of classes together with its full subcategory of sets. Like the axioms for a topos, our axiomatization is very simple, but has powerful consequences. In particular, we show that our axiomatized categories provide a sound and complete class of models for intuitionistic Zermelo-Fra... View full abstract»

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  • Region analysis and the polymorphic lambda calculus

    Publication Year: 1999, Page(s):88 - 97
    Cited by:  Papers (3)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (208 KB)

    We show how to translate the region calculus of M. Tofte and J.P. Talpin (1997), a typed lambda calculus that can statically delimit the lifetimes of objects, into an extension of the polymorphic lambda calculus called F/sub #/. We give a denotational semantics of F/sub #/, and use it to give a simple and abstract proof of the correctness of memory deallocation. View full abstract»

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  • Pattern matching as cut elimination

    Publication Year: 1999, Page(s):98 - 108
    Cited by:  Papers (2)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (225 KB)

    We present a typed pattern calculus with explicit pattern matching and explicit substitutions, where both the typing rules and the reduction rules are modeled on the same logical proof system, namely Gentzen sequent calculus for minimal logic. Our calculus is inspired by the Curry-Howard isomorphism, in the sense that types, both for patterns and terms, correspond to propositions, terms correspond... View full abstract»

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  • Some computational properties of intersection types

    Publication Year: 1999, Page(s):109 - 118
    Cited by:  Papers (1)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (176 KB)

    This paper presents a new method for comparing computation-properties of /spl lambda/-terms typeable with intersection types with respect to terms typeable with Curry types. In particular, strong normalization and /spl lambda/-definability are investigated. A translation is introduced from intersection typing derivations to Curry typeable terms; the main feature of the proposed technique is that t... View full abstract»

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  • Type inference for recursive definitions

    Publication Year: 1999, Page(s):119 - 128
    Cited by:  Papers (1)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (205 KB)

    We consider type systems that combine universal types, recursive types, and object types. We study type inference in these systems under a rank restriction, following Leivant's notion of rank. To motivate our work, we present several examples showing how our systems can be used to type programs encountered in practice. We show that type inference in the rank-k system is decidable for k/spl les/2 a... View full abstract»

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  • Plausibility measures and default reasoning: an overview

    Publication Year: 1999, Page(s):130 - 135
    Cited by:  Papers (2)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (96 KB)

    We introduce a new approach to modeling uncertainty based on plausibility measures. This approach is easily seen to generalize other approaches to modeling uncertainty, such as probability measures, belief functions, and possibility measures. We then consider one application of plausibility measures: default reasoning. In recent years, a number of different semantics for defaults have been propose... View full abstract»

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  • Subtyping recursive types in kernel Fun

    Publication Year: 1999, Page(s):137 - 146
    Cited by:  Papers (3)  |  Patents (1)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (208 KB)

    The problem of defining and checking a subtype relation between recursive types was studied in Armadio and Cardelli (1993) for a first order type system, but for second order systems, which combine subtyping and parametric polymorphism, only negative results are known. This paper studies the problem of subtype checking for recursive types in system kernel Fun, a typed /spl lambda/-calculus with su... View full abstract»

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  • A fragment calculus-towards a model of separate compilation, linking and binary compatibility

    Publication Year: 1999, Page(s):147 - 156
    Cited by:  Papers (8)  |  Patents (12)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (150 KB)

    We propose a calculus describing compilation and linking in terms of operations on fragments, i.e. compilation units, without reference to their specific contents. We believe this calculus faithfully reflects the situation within modern programming systems. Binary compatibility in Java prescribes conditions under which modification of fragments does not necessitate recompilation of importing fragm... View full abstract»

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  • Proof techniques for cryptographic processes

    Publication Year: 1999, Page(s):157 - 166
    Cited by:  Papers (17)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (264 KB)

    Contextual equivalences for cryptographic process calculi can be used to reason about correctness of protocols, but their definition suffers from quantification over all possible contexts. Here, we focus on two such equivalences, may-testing and barbed equivalence, and investigate tractable proof methods for them. To this aim, we develop an 'environment-sensitive' labelled transition system, where... View full abstract»

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  • On Hoare logic and Kleene algebra with tests

    Publication Year: 1999, Page(s):167 - 172
    Cited by:  Papers (7)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (98 KB)

    We show that Kleene algebra with tests subsumes propositional Hoare logic. Thus the specialized syntax and deductive apparatus of Hoare logic are inessential and can be replaced by simple equational reasoning. We show using this reduction that propositional Hoare logic is PSPACE-complete. View full abstract»

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  • Full abstraction and universality via realisability

    Publication Year: 1999, Page(s):174 - 182
    Cited by:  Papers (3)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (218 KB)

    We construct fully abstract realisability models of PCF. In particular, we prove a variant of the Longley-Phoa Conjecture by showing that the realisability model over an untyped /spl lambda/-calculus with arithmetic is fully abstract for PCF. Further we consider the extension of our results to a general sequential functional programming language SFPL giving rise to universal realisability models f... View full abstract»

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  • On bunched predicate logic

    Publication Year: 1999, Page(s):183 - 192
    Cited by:  Papers (4)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (170 KB)

    We present the logic of bunched implications, BI, in which a multiplicative (or linear) and an additive (or intuitionistic) implication live side-by-side. The propositional version of BI arises from an analysis of the proof-theoretic relationship between conjunction and implication, and may be viewed as a merging of intuitionistic logic and multiplicative, intuitionistic linear logic. The predicat... View full abstract»

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  • Abstract syntax and variable binding

    Publication Year: 1999, Page(s):193 - 202
    Cited by:  Papers (55)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (233 KB)

    We develop a theory of abstract syntax with variable binding. To every binding signature we associate a category of models consisting of variable sets endowed with compatible algebra and substitution structures. The syntax generated by the signature is the initial model. This gives a notion of initial algebra semantics encompassing the traditional one; besides compositionality, it automatically ve... View full abstract»

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  • Semantical analysis of higher-order abstract syntax

    Publication Year: 1999, Page(s):204 - 213
    Cited by:  Papers (35)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (196 KB)

    A functor category semantics for higher-order abstract syntax is proposed with the following aims: relating higher order and first order syntax, justifying induction principles, suggesting new logical principles to reason about higher-order syntax. View full abstract»

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  • A new approach to abstract syntax involving binders

    Publication Year: 1999, Page(s):214 - 224
    Cited by:  Papers (49)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (206 KB)

    The Fraenkel-Mostowski permutation model of set theory with atoms (FM-sets) can serve as the semantic basis of meta-logics for specifying and reasoning about formal systems involving name binding, /spl alpha/-conversion, capture avoiding substitution, and so on. We show that in FM-set theory one can express statements quantifying over 'fresh' names and we use this to give a novel set-theoretic int... View full abstract»

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  • Paramodulation with non-monotonic orderings

    Publication Year: 1999, Page(s):225 - 233
    Cited by:  Papers (2)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (156 KB)

    All current completeness results for ordered paramodulation require the term ordering > to be well-founded, monotonic and total(izable) on ground terms. Here we introduce a new proof technique where the only properties required for > are well foundedness and the subterm property: The technique is a relatively simple and elegant application of some fundamental results on the termination and c... View full abstract»

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  • Full completeness of the multiplicative linear logic of Chu spaces

    Publication Year: 1999, Page(s):234 - 243
    Cited by:  Papers (15)
    Request permission for reuse | Click to expandAbstract | PDF file iconPDF (238 KB)

    We prove full completeness of multiplicative linear logic (MLL) without MIX under the Chu interpretation. In particular we show that the cut-free proofs of MLL theorems are in a natural bijection with the binary logical transformations of the corresponding operations on the category of Chu spaces on a two-letter alphabet. View full abstract»

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